// Copyright (C) 2006, International Business Machines
// Corporation and others.  All Rights Reserved.
// This code is licensed under the terms of the Eclipse Public License (EPL).

// edwin 12/5/09 carved out of CbcHeuristicRINS

#if defined(_MSC_VER)
// Turn off compiler warning about long names
#pragma warning(disable : 4786)
#endif
#include <cassert>
#include <cstdlib>
#include <cmath>
#include <cfloat>

#include "OsiSolverInterface.hpp"
#include "CbcModel.hpp"
#include "CbcMessage.hpp"
#include "CbcHeuristicVND.hpp"
#include "CbcBranchActual.hpp"
#include "CbcStrategy.hpp"
#include "CglPreProcess.hpp"

// Default Constructor
CbcHeuristicVND::CbcHeuristicVND()
  : CbcHeuristic()
{
  numberSolutions_ = 0;
  numberSuccesses_ = 0;
  numberTries_ = 0;
  lastNode_ = -999999;
  howOften_ = 100;
  decayFactor_ = 0.5;
  baseSolution_ = NULL;
  whereFrom_ = 1 + 8 + 255 * 256;
  stepSize_ = 0;
  k_ = 0;
  kmax_ = 0;
  nDifferent_ = 0;
}

// Constructor with model - assumed before cuts

CbcHeuristicVND::CbcHeuristicVND(CbcModel &model)
  : CbcHeuristic(model)
{
  numberSolutions_ = 0;
  numberSuccesses_ = 0;
  numberTries_ = 0;
  lastNode_ = -999999;
  howOften_ = 100;
  decayFactor_ = 0.5;
  assert(model.solver());
  int numberColumns = model.solver()->getNumCols();
  baseSolution_ = new double[numberColumns];
  memset(baseSolution_, 0, numberColumns * sizeof(double));
  whereFrom_ = 1 + 8 + 255 * 256;
  stepSize_ = 0;
  k_ = 0;
  kmax_ = 0;
  nDifferent_ = 0;
}

// Destructor
CbcHeuristicVND::~CbcHeuristicVND()
{
  delete[] baseSolution_;
}

// Clone
CbcHeuristic *
CbcHeuristicVND::clone() const
{
  return new CbcHeuristicVND(*this);
}

// Assignment operator
CbcHeuristicVND &
CbcHeuristicVND::operator=(const CbcHeuristicVND &rhs)
{
  if (this != &rhs) {
    CbcHeuristic::operator=(rhs);
    numberSolutions_ = rhs.numberSolutions_;
    howOften_ = rhs.howOften_;
    numberSuccesses_ = rhs.numberSuccesses_;
    numberTries_ = rhs.numberTries_;
    lastNode_ = rhs.lastNode_;
    delete[] baseSolution_;
    if (model_ && rhs.baseSolution_) {
      int numberColumns = model_->solver()->getNumCols();
      baseSolution_ = new double[numberColumns];
      memcpy(baseSolution_, rhs.baseSolution_, numberColumns * sizeof(double));
    } else {
      baseSolution_ = NULL;
    }
    stepSize_ = rhs.stepSize_;
    k_ = rhs.k_;
    kmax_ = rhs.kmax_;
    nDifferent_ = rhs.nDifferent_;
  }
  return *this;
}

// Create C++ lines to get to current state
void CbcHeuristicVND::generateCpp(FILE *fp)
{
  CbcHeuristicVND other;
  fprintf(fp, "0#include \"CbcHeuristicVND.hpp\"\n");
  fprintf(fp, "3  CbcHeuristicVND heuristicVND(*cbcModel);\n");
  CbcHeuristic::generateCpp(fp, "heuristicVND");
  if (howOften_ != other.howOften_)
    fprintf(fp, "3  heuristicVND.setHowOften(%d);\n", howOften_);
  else
    fprintf(fp, "4  heuristicVND.setHowOften(%d);\n", howOften_);
  fprintf(fp, "3  cbcModel->addHeuristic(&heuristicVND);\n");
}

// Copy constructor
CbcHeuristicVND::CbcHeuristicVND(const CbcHeuristicVND &rhs)
  : CbcHeuristic(rhs)
  , numberSolutions_(rhs.numberSolutions_)
  , howOften_(rhs.howOften_)
  , numberSuccesses_(rhs.numberSuccesses_)
  , numberTries_(rhs.numberTries_)
  , lastNode_(rhs.lastNode_)
{
  if (model_ && rhs.baseSolution_) {
    int numberColumns = model_->solver()->getNumCols();
    baseSolution_ = new double[numberColumns];
    memcpy(baseSolution_, rhs.baseSolution_, numberColumns * sizeof(double));
  } else {
    baseSolution_ = NULL;
  }
  stepSize_ = rhs.stepSize_;
  k_ = rhs.k_;
  kmax_ = rhs.kmax_;
  nDifferent_ = rhs.nDifferent_;
}
// Resets stuff if model changes
void CbcHeuristicVND::resetModel(CbcModel * /*model*/)
{
  //CbcHeuristic::resetModel(model);
  delete[] baseSolution_;
  if (model_ && baseSolution_) {
    int numberColumns = model_->solver()->getNumCols();
    baseSolution_ = new double[numberColumns];
    memset(baseSolution_, 0, numberColumns * sizeof(double));
  } else {
    baseSolution_ = NULL;
  }
}
/*
  First tries setting a variable to better value.  If feasible then
  tries setting others.  If not feasible then tries swaps
  Returns 1 if solution, 0 if not */
int CbcHeuristicVND::solution(double &solutionValue,
  double *betterSolution)
{
  numCouldRun_++;
  int returnCode = 0;
  const double *bestSolution = model_->bestSolution();
  if (!bestSolution)
    return 0; // No solution found yet
#ifdef HEURISTIC_INFORM
  printf("Entering heuristic %s - nRuns %d numCould %d when %d\n",
    heuristicName(), numRuns_, numCouldRun_, when_);
#endif
  if (numberSolutions_ < model_->getSolutionCount()) {
    // new solution - add info
    numberSolutions_ = model_->getSolutionCount();

    int numberIntegers = model_->numberIntegers();
    const int *integerVariable = model_->integerVariable();

    int i;
    for (i = 0; i < numberIntegers; i++) {
      int iColumn = integerVariable[i];
      const OsiObject *object = model_->object(i);
      // get original bounds
      double originalLower;
      double originalUpper;
      getIntegerInformation(object, originalLower, originalUpper);
      double value = bestSolution[iColumn];
      if (value < originalLower) {
        value = originalLower;
      } else if (value > originalUpper) {
        value = originalUpper;
      }
    }
  }
  int numberNodes = model_->getNodeCount();
  if (howOften_ == 100) {
    if (numberNodes < lastNode_ + 12)
      return 0;
    // Do at 50 and 100
    if ((numberNodes > 40 && numberNodes <= 50) || (numberNodes > 90 && numberNodes < 100))
      numberNodes = howOften_;
  }
  if ((numberNodes % howOften_) == 0 && (model_->getCurrentPassNumber() <= 1 || model_->getCurrentPassNumber() == 999999)) {
    lastNode_ = model_->getNodeCount();
    OsiSolverInterface *solver = model_->solver();

    int numberIntegers = model_->numberIntegers();
    const int *integerVariable = model_->integerVariable();

    const double *currentSolution = solver->getColSolution();
    OsiSolverInterface *newSolver = cloneBut(3); // was model_->continuousSolver()->clone();
    //const double * colLower = newSolver->getColLower();
    //const double * colUpper = newSolver->getColUpper();

    double primalTolerance;
    solver->getDblParam(OsiPrimalTolerance, primalTolerance);

    // Sort on distance
    double *distance = new double[numberIntegers];
    int *which = new int[numberIntegers];

    int i;
    int nFix = 0;
    double tolerance = 10.0 * primalTolerance;
    for (i = 0; i < numberIntegers; i++) {
      int iColumn = integerVariable[i];
      const OsiObject *object = model_->object(i);
      // get original bounds
      double originalLower;
      double originalUpper;
      getIntegerInformation(object, originalLower, originalUpper);
      double valueInt = bestSolution[iColumn];
      if (valueInt < originalLower) {
        valueInt = originalLower;
      } else if (valueInt > originalUpper) {
        valueInt = originalUpper;
      }
      baseSolution_[iColumn] = currentSolution[iColumn];
      distance[i] = fabs(currentSolution[iColumn] - valueInt);
      which[i] = i;
      if (fabs(currentSolution[iColumn] - valueInt) < tolerance)
        nFix++;
    }
    CoinSort_2(distance, distance + numberIntegers, which);
    nDifferent_ = numberIntegers - nFix;
    stepSize_ = nDifferent_ / 10;
    k_ = stepSize_;
    //nFix = numberIntegers-stepSize_;
    for (i = 0; i < nFix; i++) {
      int j = which[i];
      int iColumn = integerVariable[j];
      const OsiObject *object = model_->object(i);
      // get original bounds
      double originalLower;
      double originalUpper;
      getIntegerInformation(object, originalLower, originalUpper);
      double valueInt = bestSolution[iColumn];
      if (valueInt < originalLower) {
        valueInt = originalLower;
      } else if (valueInt > originalUpper) {
        valueInt = originalUpper;
      }
      double nearest = floor(valueInt + 0.5);
      newSolver->setColLower(iColumn, nearest);
      newSolver->setColUpper(iColumn, nearest);
    }
    delete[] distance;
    delete[] which;
    if (nFix > numberIntegers / 5) {
      //printf("%d integers have samish value\n",nFix);
      returnCode = smallBranchAndBound(newSolver, numberNodes_, betterSolution, solutionValue,
        model_->getCutoff(), "CbcHeuristicVND");
      if (returnCode < 0)
        returnCode = 0; // returned on size
      else
        numRuns_++;
      if ((returnCode & 1) != 0)
        numberSuccesses_++;
      //printf("return code %d",returnCode);
      if ((returnCode & 2) != 0) {
        // could add cut
        returnCode &= ~2;
        //printf("could add cut with %d elements (if all 0-1)\n",nFix);
      } else {
        //printf("\n");
      }
      numberTries_++;
      if ((numberTries_ % 10) == 0 && numberSuccesses_ * 3 < numberTries_)
        howOften_ += static_cast< int >(howOften_ * decayFactor_);
    }

    delete newSolver;
  }
  return returnCode;
}
// update model
void CbcHeuristicVND::setModel(CbcModel *model)
{
  model_ = model;
  // Get a copy of original matrix
  assert(model_->solver());
  delete[] baseSolution_;
  int numberColumns = model->solver()->getNumCols();
  baseSolution_ = new double[numberColumns];
  memset(baseSolution_, 0, numberColumns * sizeof(double));
}

/* vi: softtabstop=2 shiftwidth=2 expandtab tabstop=2
*/
